Optical pointing system

ABSTRACT

There is provided an optical pointing system including at least one reference beacon, an image sensor, a storage unit and a processing unit. The image sensor is configured to capture an image frame containing a beacon image associated with the at least one reference beacon. The storage unit is configured to save image data of at least one object image in the image frame. The processing unit is configured to sequentially process every pixel of the image frame for identifying the object image and real-timely remove or merge the image data, saved in the storage unit, associated with two object images within a pixel range of the image frame thereby reducing the used memory space.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation application of U.S. application Ser.No. 15/077,276, filed on Mar. 22, 2016, which is a divisionalapplication of U.S. application Ser. No. 14/094,988, filed on Dec. 3,2013, the disclosure of which is hereby incorporated by reference hereinin its entirety. This application claims the priority benefit of TaiwanPatent Application Serial Number 102103386, filed on Jan. 29, 2013, thefull disclosure of which is incorporated herein by reference.

BACKGROUND 1. Field of the Disclosure

This disclosure generally relates to a human-machine interaction systemand, more particularly, to an optical pointing system.

2. Description of the Related Art

The conventional remote controller includes a plurality of press buttonsso that a user can press at least one press button thereon to generate acontrol signal so as to correspondingly control a home appliance.However, the press buttons have limited control functions and thus thepointing system for controlling home appliances by using the imagescaptured by an image sensor is developed.

A pointing system generally includes a plurality of system referencepoints for being captured by the image sensor, and a processing unit isconfigured to calculate the position variation, which will be served asa displacement, of reference point images according to the capturedimages. The displacement is used to correspondingly control a cursormotion.

When receiving an image frame, the processing unit sequentially detectsevery pixel in the image frame so as to identify whether an object imageexists in the image frame or not, and the pixel information associatedwith the object image is temporarily saved in a buffer. Referring toFIG. 1, for example three object images 91-93 are contained in an imageframe 90, wherein the object images 91 and 92 indicate the systemreference points and the object image 93 indicates the ambient noise.The processing unit saves the information of all object images 91-93into the buffer at first and then performs the post-processing, e.g.identifying which of the object images 91-93 is caused by ambientnoises.

In the above method, as the data associated with all object images inone image frame is all saved at first, a large memory space will be usedsuch that the buffer having a large memory space is required or thememory space may not be enough in some operating environments, e.g.having many ambient light sources.

Accordingly, the present disclosure further provides an optical pointingdevice that may real-timely release the occupied memory space of thebuffer.

SUMMARY

The present disclosure provides an optical pointing system that mayreduce the occupied memory space of the buffer.

The present disclosure provides an optical pointing system including atleast one reference beacon, an image sensor, a storage unit and aprocessing unit. The image sensor is configured to capture an imageframe containing a beacon image associated with the at least onereference beacon. The storage unit is configured to save image data ofat least one object image in the image frame. The processing unit isconfigured to sequentially process every pixel of the image frame withina scan period for identifying the at least one object image, and whentwo object images simultaneously appear within a clearance range of theimage frame within the scan period, remove image data, saved in thestorage unit, associated with the two object images within the clearancerange.

The present disclosure further provides an optical pointing systemincluding at least one reference beacon, an image sensor, a storage unitand a processing unit. The image sensor is configured to capture animage frame containing a beacon image associated with the at least onereference beacon. The storage unit is configured to save image data ofat least one object image in the image frame. The processing unit isconfigured to sequentially process every pixel of the image frame withina scan period for identifying the at least one object image, and when aplurality of object images simultaneously appear within a combinablerange of the image frame within the scan period, merge image data, savedin the storage unit, associated with the object images within thecombinable range.

The present disclosure further provides an optical pointing systemincluding at least one reference beacon, an image sensor, a storage unitand a processing unit. The image sensor is configured to capture animage frame containing a beacon image associated with the at least onereference beacon. The storage unit is configured to save image data ofat least one object image in the image frame. The processing unit isconfigured to sequentially process every pixel of the image frame withina scan period for identifying the at least one object image, and when acurrent object image is identified within the scan period and a previousobject image exists in the image frame, calculate an image distancebetween the current object image and the previous object image toaccordingly release a part of image data associated with the at leastone object image.

In one aspect, when an intensity of every pixel of a pixel region islarger than or equal to an intensity threshold, an accumulated pixelarea of a pixel region is larger than or equal to an area thresholdand/or a pixel region matches a predetermined feature, the processingunit identifies the pixel region as an object image, wherein the objectimage may include the beacon image and ambient light images, and thepixel region may be formed by a plurality of adjacent pixels.

In one aspect, the clearance range and the combinable range extendoutward from a center, a gravity center or an edge of an object image.

In one aspect, the clearance range and the combinable range may be afixed predetermined pixel range or determined according to systemparameters including a disposed distance between two reference beacons,an image capturing angle of the image sensor and an operable distance ofthe remote controller.

In the optical pointing system according to the embodiment of thepresent disclosure, as the processing unit may real-timely remove ormerge object image data in a predetermined pixel range within a scanperiod, a part of memory space of the storage unit is released therebysaving the system resources.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, advantages, and novel features of the present disclosurewill become more apparent from the following detailed description whentaken in conjunction with the accompanying drawings.

FIG. 1 shows a schematic diagram of an image frame captured by the imagesensor of a pointing system.

FIG. 2 shows a schematic diagram of the optical pointing systemaccording to an embodiment of the present disclosure.

FIG. 3 shows a schematic diagram of an image frame captured by the imagesensor of the optical pointing system of FIG. 2.

FIGS. 4A and 4B show schematic diagrams of the variation of image datasaved in the storage unit of the optical pointing system according tothe embodiment of the present disclosure.

FIG. 5A shows a schematic diagram of the optical pointing systemaccording to another embodiment of the present disclosure.

FIG. 5B shows a schematic diagram of an image frame captured by theimage sensor of the optical pointing system of FIG. 5A.

FIG. 6 shows a flow chart of the operating method of the opticalpointing system according to the embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENT

It should be noted that, wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

Referring to FIG. 2, it shows a schematic diagram of the opticalpointing device according to an embodiment of the present disclosure,which includes a remote controller 10 and at least one reference beacon(e.g. one reference beacon 2 is shown herein). In this embodiment, thereference beacon 2 may be a light emitting diode, a laser diode, anactive dot light source or may be formed by arranging a plurality ofactive dot light sources, and the reference beacon 2 preferably emitsidentifiable spectrum, e.g. infrared light. The remote controller 10 maybe a remote controller for home appliances on which a plurality of pressbuttons may be disposed for being pressed by a user. The user maycontrol the operation, e.g. ON/OFF and parameters output, of a homeappliance through the remote controller 10. For example in oneembodiment, the user may use the remote controller 10 to capture animage frame in which a beacon image associated with the reference beacon2 is contained, and to control a display device 8 to show the motion ofa cursor 81 according to the variation of the beacon image in the imageframe. In other embodiments, the remote controller 10 may be a portableelectronic device.

The remote controller 10 includes an image sensor 11, a processing unit12 and a storage unit 13. The image sensor 11 is preferably an activeimage sensor, e.g. a CMOS image sensor, and configured to capture animage frame IF containing a beacon image associated with the at leastone reference beacon. For example referring to FIG. 3, it shows an imageframe IF captured by the image sensor 11, wherein the image frame IFcontains a beacon image I₂.

The memory unit 13 may be a buffer configured to save image data of atleast one object image in the image frame IF, wherein the image data mayinclude parameters, e.g. the intensity, position, size and so on, of theat least one object image. In one embodiment, the storage unit 13 mayhave a plurality of storage blocks and the image data associated withdifferent object images may be respectively saved in different storageblocks.

The processing unit 12 may be a digital signal processor (DSP) and isconfigured to sequentially process every pixel of the image frame IFwithin a scan period for identifying the at least one object image,wherein the scan period may be referred to a period sequentiallydetecting every pixel of the image frame IF. For example in FIG. 3,within one scan period, the top left first pixel P_(1,1) is detected atfirst and then other pixels in the first row P_(1,2), P_(1,3) to P_(1,m)are detected sequentially, and then pixels in the second row P_(2,1) toP_(2,m) are detected sequentially, and finally pixels in the last row nP_(n,1) to P_(n,m) are detected sequentially, wherein n and m arepositive integers whose values may be determined according to thesensing array size of the image sensor 11. In addition, within the scanperiod a first pixel column may be scanned at first and then other pixelcolumns are scanned sequentially. In this embodiment, the at least oneobject image may include the beacon image I₂ and ambient light images(e.g. O₁ and O₂), wherein said ambient light may be referred to otheractive light sources in the operating environment (not the referencebeacon) or reflected light sources formed by reflecting the lightemitted by the reference beacon. Accordingly, when an intensity of everypixel of a pixel region is larger than or equal to an intensitythreshold, an accumulated pixel area (e.g. number of pixels accumulatedin the scan period having the intensity larger than or equal to theintensity threshold) of a pixel region is larger than or equal to anarea threshold and/or a pixel region matches a predetermined feature,the processing unit 12 identifies the pixel region as an object image,wherein said pixel region may be formed by one or a plurality ofadjacent pixels. Said predetermined feature may be the modulationfrequency, shape or other features configured to distinguish the beaconimage. It is appreciated that generally noises are contained in theimage frame IF and thus even though the intensity of a pixel region islarger than or equal to an intensity threshold, the pixel region may becaused by noises. Therefore, preferably a pixel region is identified asan object image when an accumulated pixel area is larger than an areathreshold at the same time. For example in FIG. 3, the intensity of thepixel P_(4,1) is larger than the intensity threshold, but the areathereof is too small (e.g. one pixel region shown herein), and thus thepixel P_(4,1) is not identified as an object image.

In this embodiment, when the processing unit 12 recognizes an objectimage, image data associated with the recognized object image istemporarily saved in the storage unit 13. Next, the processing unit 12identifies whether two object images appear within one scan period. Whentwo object images are recognized, an image distance between the twoobject images is calculated so as to determine whether to remove ormerge the image data, saved in the storage unit 13, associated with thetwo object images. For example referring to FIG. 3, when the processingunit 12 identifies a current object image O₂ (or I₂) within a scanperiod and a previous object image O₁ (or O₂) exists in the image frameIF, the processing unit 12 calculates an image distance d₁ (or d₂)between the current object image O₂ (or I₂) and the previous objectimage O₁ (or O₂) to accordingly release a part of the image dataassociated with the at least one object image. It is appreciated thatshapes and sizes of the object images in FIG. 3 are only intended toillustrate but not to limit the present disclosure.

In the present disclosure, the processing unit 12 may remove or mergeobject images that are within a predetermined pixel range so as toreduce the used memory space.

Referring to FIGS. 2, 3 and 4A, an embodiment of removing the imagedata, which is saved in the storage unit 13, associated with the objectimage is illustrated hereinafter. Herein, it is assumed that the opticalpointing system includes a single reference beacon 2 and the image frameIF captured by the image sensor 11 contains ambient light images O₁ andO₂. The processing unit 12 is configured to sequentially process everypixel of the image frame IF within a scan period for identifying the atleast one object image. When two object images (e.g. O₁ and O₂)simultaneously appear in a clearance range IR₁ of the image frame IFwithin the scan period, the image data, saved in the storage unit 13,associated with the two object images within the clearance range IR₁ isremoved.

Before the shipment of the optical pointing system of the presentdisclosure, an operable range D of the remote controller is previouslyset, such as 10 meters, but not limited to. It is also assumed thatthere is no other beacon image existing within a space range R₁ (as FIG.2) around the reference beacon 2. Accordingly, when the image sensor 11captures an image frame IF in the operable range D, a clearance rangeIR₁ in the image frame IF may be calculated according to the operablerange D and the space range R₁; that is, the clearance range IR₁ may bea fixed predetermined pixel range set previously, and the clearancerange IR₁ is a mapping of the space range R₁.

When receiving an image frame IF, the processing unit 12 sequentiallyprocesses every pixel P_(1,1) to P_(n,m). When one object image O₁ isrecognized, image data associated with the object image O₁ istemporarily saved in the storage unit 13 as the data O₁ of FIG. 4A.Next, other pixels are processed and when a current object image O₂ isrecognized, the processing unit 12 saves image data associated withcurrent object image O₂ in the storage unit 13 as the data O₂ of FIG.4A. As a previous object image O₁ exists in the image frame IF herein,the processing unit 12 then calculates an image distance d₁ between thecurrent object image O₂ and the previous object image O₁, and when theimage distance d₁ is smaller than or equal to the clearance range IR₁,the image data (as shown in FIG. 4A), saved in the storage unit 13,associated with the current object image O₂ and the previous objectimage O₁ is removed. In this embodiment, the image distance d₁ may be adistance between centers, gravity centers or edges of the current objectimage O₂ and the previous object image O₁.

In another embodiment, every time when an object image is recognized(e.g. the object image O₂ of FIG. 3), the processing unit 12 mayimmediately determine the clearance range IR₁ around the recognizedobject image, and when another object image (e.g. the object image O₁ ofFIG. 3) is recognized within the clearance range IR₁, the image data,saved in the storage unit 13, associated with the two object images(i.e. O₁ and O₂) within the clearance range IR₁ is both removed. In thisembodiment, the clearance range IR₁ is a pixel range extending outwardfrom a center, a gravity center, an edge or other positions forindicating the image position, of the at least one object image. Forexample, FIG. 3 shows the clearance range IR₁ is formed by extendingoutward from a center of the object image O₂.

Referring to FIGS, 2, 3 and 4B, an embodiment of merging the image data,which is saved in the storage unit 13, associated with the object imageis illustrated hereinafter. Herein, it is assumed that the opticalpointing system includes a single reference beacon 2, and the imageframe IF captured by the image sensor 11 contains a beacon image I₂ andan ambient light image O₂. The processing unit 12 is configured tosequentially process every pixel of the image frame IF within a scanperiod for identifying the at least one object image. When a pluralityof object images (e.g. O₂ and I₂) simultaneously appear in a combinablerange IR₂ of the image frame IF within the scan period, the image data,saved in the storage unit 13, associated with the plurality of objectimages within the combinable range IR₂ is merged.

Before the shipment of the optical pointing system of the presentdisclosure, the combinable range IR₂ is previously set. In operation,the object images within the combinable range IR₂ are merged to betreated as one single object image.

When receiving an image frame IF, the processing unit 12 sequentiallyprocesses every pixel P_(1,1) to P_(n,m). When one object image O₂ isrecognized, image data associated with the object image O₂ istemporarily saved in the storage unit 13 as the data O₂ of FIG. 4B.Next, other pixels are processed and when a current object image I₂ isrecognized, the processing unit 12 saves image data associated with thecurrent object image I₂ in the storage unit 13 as the data I₂ of FIG.4B. As a previous object image O₂ exists in the image frame IF herein,the processing unit 12 then calculates an image distance d₂ between thecurrent object image I₂ and the previous object image O₂, and when theimage distance d₂ is smaller than or equal to the combinable range IR₂,the image data, saved in the storage unit 13, associated with thecurrent object image I₂ and the previous object image O₂ is merged (e.g.FIG. 4B showing the data O₂ and data I₂ being merged as data O). In thisembodiment, the image distance d₂ may be a distance between centers,gravity centers or edges of the current object image I₂ and the previousobject image O₂.

In another embodiment, every time when an object image is recognized(e.g. the object image I₂ of FIG. 3), the processing unit 12 mayimmediately determine the combinable range IR₂ around the recognizedobject image, and when another object image (e.g. the object image O₂ ofFIG. 3) is recognized within the combinable range IR₂, the image data,saved in the storage unit 13, associated with the two object imageswithin the combinable range IR₂ is merged. It should be mentioned thatalthough FIG. 3 shows that a combinable range IR₂ contains only twoobject images, it is appreciated that when more than two object imagesare contained within the combinable range IR₂, the more than two objectimages may also be merged as one single object image. The combinablerange IR₂ is a pixel range extending outward from a center, a gravitycenter, an edge or other positions for indicating the image position ofthe at least one object image. For example, FIG. 3 shows the combinablerange IR₂ is formed by extending from a center of the object image I₂.

In another embodiment, it is assumed that the optical pointing systemincludes two reference beacons, and the processing unit 12 may determinethe clearance range IR₁ and the combinable range IR₂ according to thesystem parameter. For example referring to FIGS. 5A and 5B, FIG. 5Bshows a schematic diagram of an image frame IF′ captured by the imagesensor 11. Two reference beacons 2 and 2′ are separated by a disposeddistance d, and an operable distance of the remote controller 10 isassumed to be D. The image frame IF′ captured by the image sensor 11 maycontain two beacon images I₂ and I₂′. In addition, other object imagesO₃ and O₄ as well as O₅ and O₆ are shown in FIG. 5B for illustration. Itis assumed that an image distance between the two beacon images I₂, I₂′is d′ and there is no other object image existing within the range d′.Therefore, the clearance range IR₁ of the present disclosure may be setas equal to or slightly smaller than the image distance d′. However, asthe image distance d′ changes with system parameters including thedisposed distance d, the operable distance D (e.g. 1-10 meters), animage capturing angle θ of the image sensor 11 and so on, the processingunit 12 may calculate the clearance range IR₁ according to the systemparameters. The combinable range IR₂ may be set as a ratio or an offsetof the clearance range IR₁. In another embodiment, the clearance rangeIR₁ and the combinable range IR₂ may be a fixed predetermined pixelrange set previously. In addition, besides the method of determining theclearance range IR₁ and the combinable range IR₂, other details aresimilar to FIG. 3 and corresponding descriptions thereof and thus theyare not repeated herein.

In other words, the clearance range IR₁ and the combinable range IR₂according to the embodiment of the present disclosure may be fixedpredetermined pixel ranges or determined according to the systemparameters, wherein the system parameters may include a disposeddistance between reference beacons, an image capturing angle of theimage sensor and an operable distance. For example, it is assumed thatthe operable distance is 1-10 meters, and the distance (e.g. d′) betweentwo beacon images in the captured image frames associated with differentimage capturing angles θ within the operable distance may be previouslymeasured, and the image capturing angle θ may be real-timely calculatedduring operation. In this manner, after the processing unit 12 obtainsthe distance between beacon images and the image capturing angle θ ofthe image sensor according to the image frame, the actual distancebetween the remote controller 10 and the reference beacons 2, 2′ may beobtained by using a lookup table or the algorithm to accordinglydetermine the clearance range IR₁ and the combinable range IR₂.

Referring to FIG. 6, it shows a flow chart of the operating method ofthe optical pointing system according to the embodiment of the presentdisclosure, which includes the steps of: capturing an image frame (StepS₃₁); recognizing object images in the image frame (Step S₃₂); comparingan image distance with a distance threshold (Step S₃₃); performingobject tracking when the image distance is larger than the distancethreshold (Step S₃₄); and merging or removing image data associated withtwo object images when the image distance is smaller than or equal tothe distance threshold (Step S₃₅); wherein the distance threshold mayinclude the aforementioned clearance range (e.g. the first threshold)and/or combinable range (e.g. the second threshold). Referring to FIGS.2-5B, the operating method of this embodiment is illustratedhereinafter.

Step S₃₁: The image sensor 11 captures an image frame (e.g. FIG. 3 or5B) to be sent to the processing unit 12.

Step S₃₂: The processing unit 12 performs the recognition of objectimage according to the pixel intensity, the accumulated pixel area andthe predetermined feature of a pixel region of adjacent pixels, e.g.recognizing the object images O₁, O₂, I₂ of FIG. 3 and the object imagesI₂, I₂′, O₃-O₆ of FIG. 5B, wherein the method of recognizing the objectimage is well known, and the present disclosure is to merge or removethe recognized object images.

Step S₃₃: The processing unit 12 then compares the image distancebetween the object images O₁ and O₂ (e.g. assuming only object images O₁and O₂ being included) or the image distance between the object imagesO₂ and I₂ (e.g. assuming only object images O₂ and I₂ being included)with the distance threshold, wherein the image distances d₁ and d₂ maybe distances between centers, gravity centers, edges or other positionsfor indicating the object image position of the two object images.

Step S₃₄: When the processing unit 12 identifies that the image distanceis larger than a first threshold (e.g. the clearance range IR₁), the twoobject images (e.g. object images I₂ and I₂′ of FIG. 5B) are treated astwo different objects. The processing unit 12 then performs the objecttracking on the two objects, e.g. calculating object coordinatesaccording to the image frame or calculating an object displacementaccording to the image frame and a previous image frame, wherein methodsof calculating the object coordinate and the object displacement arewell known and thus details thereof are not described herein.

Step S₃₅: When the processing unit 12 identifies that the image distanceis smaller than or equal to a first threshold and larger than a secondthreshold (e.g. the combinable range IR₂), image data associated withtwo object images (e.g. the object images O₃ and O₄ of FIG. 5B) andsaved in the storage unit 13 is removed. When the processing unit 12identifies that the image distance is smaller than or equal to thesecond threshold, image data associated with two object images (e.g. theobject images O₅ and O₆ of FIG. 5B) and saved in the storage unit 13 ismerged thereby reducing the occupied memory space. When the object imagewithin a predetermined pixel range is removed or merged, the processingunit 12 then performs the object tracking according to the left objectimage(s) and/or the merged object image(s). In this embodiment, thesecond threshold may be smaller than the first threshold.

In the present disclosure, the step of removing object data and the stepof merging object data may be performed independently or simultaneously.

It should be mentioned that although one and two reference beacons areused to illustrate in the embodiment of the present disclosure, it isnot to limit the present disclosure. The number of the reference beaconsmay be determined according to the algorithm for calculating thedisplacement and coordinate without particular limitation. The presentdisclosure is to release at least a part of memory space associated witha plurality of object images when the remote controller 10 recognizesthe plurality of object images appear within a clearance range or acombinable range thereby reducing the occupied memory space.

In addition, although FIGS. 4A and 4B show that the image data are savedcontinuously, they are only intended to illustrate but not to limit thestorage method of the image data in the storage unit 13.

As mentioned above, the conventional pointing device temporarily savesall object images that are recognized at first and then identifies,after the scanning ended, whether the saved object images are associatedwith the system reference beacons such that a larger memory space can beoccupied in operation. Therefore, the present disclosure furtherprovides an optical pointing device (FIGS. 2 and 5A) that may releasethe memory space for recording ambient light data during scanning theimage frame thereby reducing the used memory space.

Although the disclosure has been explained in relation to its preferredembodiment, it is not used to limit the disclosure. It is to beunderstood that many other possible modifications and variations can bemade by those skilled in the art without departing from the spirit andscope of the disclosure as hereinafter claimed.

What is claimed is:
 1. An optical pointing system, comprising: a singlereference beacon; an image sensor configured to capture an image framecontaining at least a beacon image associated with the single referencebeacon; a storage unit configured to store image data of at least oneobject image, which comprises the beacon image, in the image frame; anda processing unit configured to sequentially process every pixel of theimage frame within a scan period for identifying the at least one objectimage, and when a current object image is identified next to a previousobject image being identified in the image frame within the scan period,calculate an image distance between the current object image and theprevious object image to release a part of the image data associatedwith the at least one object image according to the calculated imagedistance, wherein the current object image and the previous object imageare separated from each other without being connected by any objectimage in the image frame.
 2. The optical pointing system as claimed inclaim 1, wherein the at least one object image further comprises anambient light image.
 3. The optical pointing system as claimed in claim1, wherein when an intensity of every pixel of a pixel region is largerthan or equal to an intensity threshold and at least one of (i) a pixelarea of the pixel region being larger than or equal to an areathreshold, and (ii) the pixel region matching a predetermined feature,is true, the processing unit is configured to identify the pixel regionas the at least one object image.
 4. The optical pointing system asclaimed in claim 1, wherein the processing unit is further configured toremove image data, stored in the storage unit, associated with thecurrent object image and the previous object image when the calculatedimage distance is smaller than or equal to a first threshold.
 5. Theoptical pointing system as claimed in claim 4, wherein the firstthreshold is a fixed predetermined pixel range.
 6. The optical pointingsystem as claimed in claim 4, wherein the first threshold is determinedaccording to system parameters, which are selected from the groupconsisting of an image capturing angle of the image sensor and apredetermined operable range of the optical pointing system.
 7. Theoptical pointing system as claimed in claim 1, wherein the processingunit is further configured to merge image data, stored in the storageunit, associated with the current object image and the previous objectimage when the calculated image distance is smaller than or equal to asecond threshold.
 8. The optical pointing system as claimed in claim 7,wherein the second threshold is a fixed predetermined pixel range. 9.The optical pointing system as claimed in claim 7, wherein the secondthreshold is determined according to system parameters, which areselected from the group consisting of an image capturing angle of theimage sensor and a predetermined operable range of the optical pointingsystem.
 10. The optical pointing system as claimed in claim 1, whereinthe calculated image distance is a distance between centers, gravitycenters or edges of the current object image and the previous objectimage.
 11. A remote controller, comprising: an image sensor configuredto capture an image frame containing at least one object image; astorage unit configured to store image data of the at least one objectimage in the image frame; and a processing unit configured tosequentially process every pixel of the image frame within a scan periodfor identifying the at least one object image, and when a current objectimage is identified within the scan period and a previous object imageexists in the image frame, calculate an image distance between thecurrent object image and the previous object image to release a part ofthe image data associated with the at least one object image accordingto the calculated image distance, wherein the current object image andthe previous object image are separated from each other without beingconnected by any object image in the image frame.
 12. The remotecontroller as claimed in claim 11, wherein the at least one object imagecomprises a reference beacon image and an ambient light image.
 13. Theremote controller as claimed in claim 11, wherein when an intensity ofevery pixel of a pixel region is larger than or equal to an intensitythreshold and at least one of (i) a pixel area of the pixel region beinglarger than or equal to an area threshold, and (ii) the pixel regionmatching a predetermined feature, is true, the processing unit isconfigured to identify the pixel region as the at least one objectimage.
 14. The remote controller as claimed in claim 11, wherein theprocessing unit is configured to remove image data, stored in thestorage unit, associated with the current object image and the previousobject image when the calculated image distance is smaller than or equalto a first threshold.
 15. The remote controller as claimed in claim 14,wherein the first threshold is a fixed predetermined pixel range. 16.The remote controller as claimed in claim 14, wherein the firstthreshold is determined according to system parameters, which areselected from the group consisting of an image capturing angle of theimage sensor and a predetermined operable range of the remotecontroller.
 17. The remote controller as claimed in claim 11, whereinthe processing unit is configured to merge image data, stored in thestorage unit, associated with the current object image and the previousobject image when the calculated image distance is smaller than or equalto a second threshold.
 18. The remote controller as claimed in claim 17,wherein the second threshold is a fixed predetermined pixel range. 19.The remote controller as claimed in claim 17, wherein the secondthreshold is determined according to system parameters, which areselected from the group consisting of an image capturing angle of theimage sensor and a predetermined operable range of the remotecontroller.
 20. The remote controller as claimed in claim 11, whereinthe calculated image distance is a distance between centers, gravitycenters or edges of the current object image and the previous objectimage.